Answer:
4
Step-by-step explanation:
ΔABC is congruent with ΔDEF. That means the corresponding sides are congruent.
Look at the order of the letters. EF are the last two letters of ΔDEF. So this corresponds with the last two letters of ΔABC. Therefore, EF ≅ BC.
EF ≅ BC
x² + 8x = 48
x² + 8x − 48 = 0
(x + 12) (x − 4) = 0
x = -12 or 4
Since x can't be negative, x = 4.
